Extracting bridge frequencies and damping ratios using damped vibrations of a non-moving vehicle

While increasing endeavors have been made to develop efficient bridge damage inspection methods using vehicles as conveniently deployable sensors, accurately identifying bridge frequencies and damping ratios from vehicle responses remains a challenging task. By using the damped vibration of the non-moving vehicle-bridge system excited by a vehicle passing through the bridge, this study proposes a novel method for indirectly extracting bridge frequencies and damping ratios from the response of a non-moving vehicle parked on the bridge. Theoretical analyses of the non-moving vehicle-bridge system reveal how bridge vibrations are reflected in the response of the non-moving vehicle, leading to the development of a signal processing algorithm for automatically extracting bridge frequencies and damping ratios. Several numerical studies are conducted to assess the applicability of the proposed method and provide insights for real-world implementations, which are further validated through laboratory experiments. The results indicate that the proposed method is more robust in extracting bridge frequencies and damping ratios from vehicle responses than existing counterparts. Notably, the proposed method does not require stringent testing conditions, such as precise vehicle properties, specific bridge conditions, or low measurement noise, making it highly promising for future real-world applications. However, it is advised to avoid “trapping locations” during testing and to use a non-moving vehicle with low damping for optimal results.